Plants for the treatment of plates for electronic circuits, for example silicon based or alumina based wafers, in particular for photovoltaic cells or for green-tape type circuits, are known, which comprise at least a testing device to carry out a quality test on said plates. By quality test we mean, for example but not exclusively, to verify the capacity of said plates to conduct electric current or the capacity of said plates to tolerate a determinate level of intensity of the electric current.
These known devices comprise transport means, able to transport the plates from a previous work station to a testing station, in correspondence with which a testing means is disposed, for example an automated electromechanical arm provided at one end with a plurality of sensors able to measure the intensity of electric current. The known devices also comprise a TV camera able to detect the position of the plate on the testing station and a processing and command unit able to receive and to process the information arriving from the TV camera to command the positioning of the testing means in order to dispose said means aligned and in axis with the plate, so as to be able to achieve an effective testing process.
One disadvantage of these known testing devices is that, in order to guarantee effective and accurate measurement, their position must be correct and centered with respect to the position of the plate. Therefore, the testing means is complex, and requires the use of high quantities of energy and materials in order to guarantee correct positioning in every stage of the testing; it also needs frequent and laborious maintenance operations so that it can function correctly. Furthermore, the need to correct the position of the testing means substantially for every plate to be tested causes a slow-down in the testing process and consequently an increase in production times.
Purpose of the present invention is to achieve a testing device to test plates for electronic circuits that requires the use of reduced quantities of energy and materials, that does not need frequent and laborious maintenance operations and that speeds up the testing process and consequently increases productivity.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.